In commonly owned application Ser. No. 533,219, filed by me jointly with Manfred Posselt on 16 Dec. 1974, there has been disclosed a mechanism for transporting a three-layer stack to a platen press, the mechanism including a carriage with two sets of clamps whose jaws engage opposite stack edges after the clamps have been swung toward these edges about pivotal axes parallel thereto. In an earlier commonly owned application, Ser. No. 348,013 filed 5 Apr. 1973 by Manfred Posselt, now U.S. Pat. No. 3,909,343 a laminating press is described whose platens are laterally recessed to accommodate such jaws whereby the stack can remain clamped during the laminating operation.